Carbureting apparatus particularly suitable for use upon aircraft



Sept. s, 1925.

R. L. G. LE GRAIN CARBURETING APPARATUS PARTICULARLY SUITABLE FOR USE UPON AIRCRAFT Filed June 16, 1924 2 Sheets-Sheet. 1

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A Q i //1 V617 for find KW Sept. 8, 1925. 1,553,249

R. L. G. LE GRAIN CARBURETING APPARATUS PARTICULARLY SUITABLE FOR USE UPON AIRCRAFT Filed June 16, 1 924. 2 Sheets-Sheet. 2

Patented Sept. 8, 1925.

UNITED STATES PATENT OFFICE.

nnm nucmn ens'rnvn LE GRAIN, or rams, marten.

CARBURETING APPARATUS PARTICULARLY SUITABLE FOR USE UPON AIRCRAFT.

a ease filed June 16, 1924. Serial No. 720,402.

The before mentioned invention refers to carbureting apparatus for use with internal combustion engines and more particularly suitable for use upon aircraft, comprising a primary carburetor element in close proximity to the engine and furnished with means for admitting air, a secondary carburetor element in close roximity to the float chamber or its equiva ant and at a considerable distance from the first mentioned element and having means for admitting air, the primary and secondary elements being connected by a long conduit which may be heated by means of a water jacket, or by electricity.

The present invention refers more particularly to improved constructional embodiments rendering-the invention particularly suitable for use upon aircraft. 7

According to the invention in'place of providing simple air admission ports or P113- sages iuconnection with the primary and seconds carburetor elements, each element is provi ed with two admission orifices, one of which communicates with the outer air and the other either with the space within the hood or casing of the aircraft, or with a conduit opening into the atmosphere, but allowing on y the admission of air of reduced pressure; said conduit might receive the form of a venturi.

Flaps or shutters are provided in connec-- tion with the passages for allowing for the progressive opening and closing of one or other of the openings and/or for the progressive opening of one and closing of the other. i I v Means are also added for separating the compartment containing the engine from the secondary carburetor and for ensuring that conflagration shall not be caused even in the case of a serious backfire.

In order that the present invention may be more clearly understood, it will now be described with reference to the accompanying drawing, which shows by .way of example, a construction made according to the invention.

Fig. 1 is a sectional elevation of one constructional embodiment.

Fig. 2 is a similar view of another constructional embodiment.

Referring to Fig. 1, A denotes the cistern or reservoir of the float chamber. To this float chamber is connected the special-secondary carburetor element described in the specification of the original application.

A denotes. the outlet ipe or saturated mixture which pipe lea s into the heater tube E, forming the long connection with the primary carburetor element. This tube may be surrounded by a heating jacket E.-

G denbtes the pi e for the admission of air for supplying t e secondary carburetor element in connect-ion with the chamber A. B is the primary carburetor element and I is the corresponding passage for drawing 1n air.

According to the resent invention each of the passages G an I is provided with two openings respectively I I and G, G.

One of these passa es or openings puts the conduit with whic it is associated into communication with the outer air and the other into communication with the closed space within the cowl of the aircraft, or with a tube I, the arrangement and direction of which is such as to allow only of admitting air of reduced pressure.

Either of these passages may be closed at will by means of a single shutter J, for the passages I, and K for the passage G.

. This arrangement allows for the regulation of the carburetor for normal working up to a determined altitude, for instance 2000 meters with air of reduced pressure, drawn in under the cowl, or through the conduit I, that is to sa air which is not compressed or influence by the 'movement of translation of the aircraft and/or the rotary motion of the propeller.

At greater altitudes the flaps or shutters which would be in the positions indicated gressively into the positions in which t ey .uncover the openings I and. G for communicating with the draught of compressed air on the outside.

The result is that there is a progressively increasing intake of air from air at high pressure flowing on the exterior, uniting with air at reduced pressure drawn in under the cowl, or through the conduit 1, which permits carburation to be effected as a function of the altitude by replacing air which is not compremed or which is under normal pressure by increasing quantities of compressed air.

The shutters or fla s J and K may be operated separately or om a single control.

In addition, as will be seen from the drawing, the whole group of set of parts located at a long distance from the element B, that is to say the parts A-A constituting the secondary carburetor element and float chamber and if desired the passage G in connection with the secondary carburetor may be separated from the engine chamber by a partition or shield L which constitutes an intercepting means preventing the access of the flames to the grou of parts in question however serious the back ring or the flames driven back owing to the current of air..

. In place of a special partition, some existin partition might be used, the connecting tube separating the element, that is the tube EE always passing through the said partition.

In some cases and as shown in the modification illustrated at Fig. 2, it sufiices to provide a shield M enclosing the group of parts AA in the locality where leakages of etrol might take place. 1 The shield mig t for instance be attached to an existing chamber or to the body of thesecondary carburetor.

The bottom of the enveloping shield should comprise a draina 'e orifice in connection with a pipe or con uit m opening on the outside of the casing.

. erably What I claim as my invention and desire to secure by Letters Patent of the United States of America is z- 1. In a carburetin apparatus for use upon aircraft, the com ination of a primary carburetor element in close proximity to the en 'ne, an air admission passage to the said car uretor, such passage being rovided with two inlet openings, one of which communicates with the outer air and the other of which communicates with the air on the in terior of the cowl or covering of the aircraft, a secondary carburetor element in close proximity to a float chamberor its equivalent, an air admission passage to the said secondary carburetor element, such passage being provided with two openin one of which opens to the outer air and tih e other of which opens to'the air on the interior of the cowl or coveri of the aircraft, and a long conduit w ich may be heated in any suitable manner connecting the outlet of the secondary carburetor ele ment to the inlet of the primary element, for the purposes set forth.

2. In a carbureting apparatus as claimed in claim 1, a construction in which a single shutter is provided in connection with each of the air passages for closing either the opening to the outer air or that to the interior of the aircraft, for the purposes set forth.

3. In an aircraft provided with a carburetor as claimed in claim 1, a construction in which the secondary carburetor and its associated parts is separated from the primary carburetor and the engine chamber by a partition through which the" connecting conduit passes, for the purposes set forth.

4. In an aircraft as claimed in claim 3, a. construction in which the secondary carburetor is enclosed in a shield which is prefprovided with an outlet orifice in connection with a tube opening to the outside, for the escape of any petrol leaking from the float chamber or carburetor.

In witness whereof I aflix my signature.

RENE LUCIE GUSTAVE LE GRAIN. 

